Lung cancer incidence rates among Jews in Israel are significantly lower than in most developed countries in the world. A more detailed analysis of the rates among different Jewish ethnic groups also showed low rates. While Jewish males born in Europe-America (EA) had an 11% increase in rates between 1962-66 and 1977-82, Jewish males from Asian-African (AA) origin had a 45% increase resulting in current higher rates among North African than among East European Jews (the two dominant ethnic groups in Israel). In Jewish females, rates have been relatively stable from 1972 to 1982 and were almost twice as high for females born in EA than females born in AA with less prominent differences between countries. While smoking patterns probably explain the increase in rates among Asian-African Jewish males, other possible risk factors as well as the overall smoking prevalence cannot explain the low incidence in the major ethnic Jewish groups. The possibility of differed susceptibility is raised.